Method of,and an apparatus for,obtaining measurements which correspond to the substance cross-section of textile material



E. FELIX METHOD OF. AND AN APPARATUS FOR OBTAINING MEASUREMENTS WHICHCORRESPOND TO THE SUBSTANCE CROSS-SECTION 0F TEXTILE MATERIAL FiledApril 28, 1967 United States Patent 3,435,673 METHOD OF, AND ANAPPARATUS FOR, OBTAIN- ING- MEASUREMENTS WHICH CORRESPOND TO THESUBSTANCE CROSS-SECTION 0F TEX- TILE MATERIAL Ernst Felix, Uster,Switzerland, assignor to Zellweger, Ltd., Uster, Switzerland Filed Apr.28, 1967, Ser. No. 634,654 Claims priority, application Switzerland, May6, 1966, 6,663/ 66 Int. Cl. G011 5/04 US. Cl. 73-160 Claims ABSTRACT OFTHE DISCLOSURE Method and apparatus for measuring the substancecross-section of textile material, slivers in particular, in which thetextile material is drawn at a predetermined speed through a nozzlehaving at least one constriction, pneumatic pressure generated at theconstriction being evaluated as the measured quantity relating to thesubstance cross-section of the textile material.

Background of the invention Suitable measuring systems for determiningsubstance cross-section of textile material are extremely important toquality control in the textile industry insofar as they enable themanufacturing processes to be monitored and regulated on the basis ofthe results that are provided. At present, the only measuring systems ofthis type in common use are capacitive and optical measuring systems.The principal disadvantage of a capacitive system is that it issensitive to the moisture content of the textile material and thereforedoes not provide consistently accurate measurement. In addition to this,the zero or neutral point is not stable enough to insure dependabilityof operation. In optical measuring systems, difficulties are encountereddue to lack of stability in both phototransmitters and photo-receivers.In addition to capacitive and optical measuring systems, it has alreadybeen proposed as a result of extensive tests to take measurements on theprinciple of the absorption of radio-active rays by the textilematerial. Unfortunately, none of these proposals has had any practicalapplications for a variety of reasons.

Brief description of the invention The present invention has an objectto obviate the disadvantages inherent in known devices, as indicatedabove, and relates to a method of obtaining measurements correspondingto the substance cross-section of textile material, slivers inparticular, in which the textile material is drawn at a predeterminedspeed through a nozzle having at least one constriction, pneumaticpressure generated at the constriction being evaluated as the measuredquantity relating to the substance crosssection of the textile material.The invention also provides an apparatus for carrying out this method,comprising a nozzle through which the textile material can travel andwhich tapers in cross-section in the direction of movement of thetextile material and has a hollow or empty space between two planeslying one behind the other, extending vertically of its axis, and amanometer connected to this empty space for determining a quantityrelating to the pneumatic pressure in the hollow or empty space.

It is an object of the present invention to provide method and apparatusfor obtaining measurements of the substance cross-section of textilematerial which is dependable and consistently accurate in operation.

It is another object of the present invention to provide a method andapparatus as described wherein variable ice properties of air, such astemperature and pressure, are eliminated automatically as factors in themeasurement.

It is a further object of the present invention to provide a method andapparatus as described wherein the measurement of a silver of textilematerial is accomplished by measurement of the air derived from abruptreduction in the cross-section of the sliver.

It is an object of the present invention to provide an apparatus of thetype described which is capable of producing a measurement independentof the rate of movement of the sliver of textile material.

These and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription thereof when taken in conjunction with the accompanyingdrawings wherein:

FIGURE 1 shows a cross-section of a basic nozzle arrangement inaccordance with the invention,

FIGURE 2 is a section through a funnel-shaped nozzle (trumpet),

FIGURE 3 shows a trumpet of the kind shown in FIG- URE 2 with an annularwidened portion,

FIGURE 4 shows a trumpet with groove machined into it, and

FIGURE 5 shows a measuring system with a nozzle and pressurecompensation in accordance with the invention.

Detailed description of the invention In the method according to theinvention, textile material 5 is drawn through two substantiallyconcentric apertures 1 and 2 lying one behind the other, as shown inFIGURE 1. The aperture 2 is smaller in diameter than the aperture 1 sothat after passing through the aperture 1, the textile material iscompressed by the aperture 2. A certain amount of air is trapped in theconstituent fibrous material of the sliver, and passes through theapertures together with the textile material. If the fibre crosssectionis the same in both the apertures 1 and 2, a quantity of air whichcorresponds both to the rate of flow of the textile material and to thediflerence in cross-section of the two apertures, must be forced out ofthe mass of fibres during passage from the aperture 1 to aperture 2.This air escapes into the chamber 3, if possible; however, if thechamber 3 is completely, or at least partly, closed, all or part of theair must escape longitudinally through the sliver.

A fairly large substance cross-section generates a fairly high airresistance and accordingly a relatively high pressure in the chamber 3which can be detected through a manometer, for example, connected to thechamber at an opening 4 in this chamber. The air resistance could ofcourse also be measured with compressed air introduced into the chamber.In the present method, however, the measuring medium itself supplies anactive quantity of air pressure, which must be regarded as a.substantial advantage.

Elements for constricting the fibre-cross-section of slivers are knownper se and are commonly used in many textile machines, being referred totherein as condensers or trumpets. FIGURE 2 is a section through oneembodiment of such a trumpet having a central passage which is reducedcontinuously in cross-section. It is of particular advantage to designthese trumpets in accordance with the present invention wherein thecentral passage is provided with successive concentric apertures ofditferent size producing an abrupt reduction in the passage so that theycan be used as measuring elements, as shown in FIGURE 3. An annularwidened portion 7 is provided in the wall of the trumpet in such a waythat a first crosssection has a diameter ti, and a second cross-sectiona smaller diameter d The widened portion 7 may communicate with amanometer or other measuring device (not shown) through a nipple 6.

A particularly simple form of trumpet, as seen in FIG- URE 4, isobtained by machining a groove 8 into the walls of the central passageand providing a radial bore 9 in communication therewith for theconnection of a pressure gauge to the chamber formed by the groove 8. Ofcourse, other nozzle configurations may be provided utilizing theprinciples set forth herein without departing from the spirit and scopeof the present invention.

The pressure generated in the chamber 3 is, however, not only governedby the extent to which the sliver is constricted as it passes from theaperture 1 to the aperture 2, but also by the rate at which the sliveris pulled through the nozzle. To allow for this factor in themeasurement, a unit of the kind shown in FIGURE 5, for example, may beprovided for producing a diiferential measurement; it comprises an aircompressor 14 driven at a rotational speed proportional to the rate ofpassage of the sliver through the nozzle 11. If the pressure generatedin the compressor 14 is applied in opposition to the pressure in thechamber 3, selectively through a regulating valve 13, for example in adifferential manometer 12, the ratio between the pressure in the chamber3 as applied to arm of the manometer, and the pressure in the arm 16 ofthe manometer 12 derived from compressor 14 via valve 13 will provide anindication of the substance cross-section. The ditferential method usinga compressor 14 is also of advantage insofar as the variable propertiesof the air, such as temperature and barometric pressure, areautomatically taken into consideration and eliminated as factors in themeasurement.

In cases where a regulating system is used, the regulating valve 13 alsoenables a desired value to be set for the substance cross-section to bemeasured in that a rise in pressure in the arm 16 requires an increasingsubstance cross-section in the trumpet 11 and vice versa.

In order to derive a signal from the pressure difference measured in themanometer 12, a suitable converter means 18 known per se may be providedwhich converts the level of the manometer column 17 or its fluctuationsinto a suitable measured quantity which may be obtained as an electricalsignal.

I have shown and described several embodiments in accordance with thepresent invention. It is understood that the same is not limited theretobut is susceptible of numerous changes and modifications as known to aperson skilled in the art and I, therefore, do not wish to be limited tothe details shown and described herein.

I claim:

1. A method of obtaining measurements corresponding to the substancecross-section of a sliver of textile material comprising guiding thetextile material through a nozzle having at least one relatively abruptconstriction in cross-section, whereby air is discharged from thetextile material at said constriction, and

measuring the air pressure generated by said discharge of air at saidconstriction.

2. A method as defined in claim '1 wherein said step of measuringincludes providing a counter air pressure corresponding to the desiredvalue of the substance crosssection of the textile material andcomparing the generated air pressure with the counter air pressure toobtain a resultant value.

3. A method as defined in claim 2 further comprising converting saidresultant value to an electrical signal.

4. A method of obtaining measurements corresponding to the substancecross-section of textile material, slivers in particular, comprisingmoving said textile material at a prescribed rate along a given path,

abruptly restricting the cross-section of said textile material at apoint along said path, and

measuring the pressure of the air forced out from said textile materialas a result of the restriction of the cross-section thereof. 5. A methodas defined in claim 4 further comprising the steps of providing acounter air pressure having a magnitude proportional to the rate ofmovement of the textile material and comparing the emitted air pressurewith the counter air pressure to obtain a resultant value. 6. A methodas defined in claim 5 further comprising converting said resultant valueto an electrical signal.

7. An apparatus for obtaining measurements corresponding to thesubstance cross-section of textile material, slivers in partcular,comprising a nozzle having a central through-passage, saidthroughpassage having a relatively abrupt reduction in crosssection atan area along its length in the direction of movement of textilematerial therethrough, and

measuring means connected to said nozzle for measuring the air pressurecreated in said through-passage at the point of said abrupt reduction incross-section by the compression of said textile material by said abruptreduction in cross-section.

8. An apparatus as defined in claim 7 wherein said through-passagetapers gradually toward its axis from one end to the other in thedirection of movement of textile material therethrough with theexception of said area of abrupt change in cross-section.

9. An apparatus as defined in claim 7 wherein said .nozzle furtherincludes a chamber positioned between two parallel planes transverse tothe axis of said throughpassage at the area of abrupt reduction incross-section thereof, said measuring means being connected to saidchamber.

10. An apparatus as defined in claim 9 wherein said through-passagetapers gradually toward its axis and said chamber is provided as anannular groove in the surface of said through-passage.

11. An apparatus as defined in claim 10 wherein said nozzle furtherincludes a transverse bore communicating with said chamber, saidmeasuring means being connected to said bore.

12. An apparatus as defined in claim 9 wherein said measuring meansincludes a differential manometer having a first inlet connected to saidchamber and a second inlet, a compressor providing a counter airpressure connected to the second inlet of said manometer.

13. An apparatus as defined in claim 12 wherein said measuring meansfurther includes a regulating valve connected between said compressorand said second inlet of said manometer.

14. An apparatus as defined in claim 13 wherein said measuring meansfurther includes converter means for converting the reading of saidmanometer into measured quantities corresponding to the substancecross-section of the textile material.

15. An apparatus as defined in claim 7 wherein said measuring meansincludes a manometer connected to said nozzle for measuring air pressurein said through-passage.

References Cited UNITED STATES PATENTS Biddison 73-37.7

LOUIS R. PRINCE, Primary Examiner.

J. NOLTON, Assistant Examiner.

US. Cl. X.R. 73-37.7

